<template>
  <div class="xtx-carousel" @mouseenter="stop" @mouseleave="onPlay">
    <ul class="carousel-body">
      <li class="carousel-item" v-for="(item, index) in slides" :key="item.id" :class="{ fade: active === index }">
        <RouterLink :to="item.hrefUrl">
          <img :src="item.imgUrl" alt="" />
        </RouterLink>
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="toggle(-1)">
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a href="javascript:;" class="carousel-btn next" @click="toggle(+1)">
      <i class=" iconfont icon-angle-right"></i>
    </a>
    <div class="carousel-indicator">
      <span v-for="(item, index) in slides" :key="item.id" :class="{ active: active === index }"
        @click="active = index"></span>
    </div>
  </div>
</template>

<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data'
import { onBeforeMount, onMounted, ref } from "vue";
// 1.第一种写法
// import { PropType } from 'vue'
// defineProps({
//   slides: {
//     type: Array as PropType<BannerItem[]>,
//     required: true,
//   },
//   autoPlay: {
//     type: Boolean,
//     default: false
//   },
//   duration: {
//     type: Number,
//     default: 3000
//   }
// })
// 2.第二种写法
const { slides, autoPlay = false, duration = 3000 } = defineProps<{
  slides: BannerItem[],
  autoPlay?: Boolean,
  duration?: number
}>()
// 控制高亮的下标
const active = ref(0)
// 箭头切换
const toggle = (step: number) => {
  active.value += step
  // 超过数据的数量
  if (active.value > slides.length - 1) {
    active.value = 0
  }
  // 小于0，不能小于 0
  if (active.value < 0) {
    active.value = slides.length - 1
  }

}
// 点击轮播图左箭头
// const onPrev = () => {
//   if (active.value <= 0) {
//     active.value = slides.length - 1
//   } else {
//     active.value--
//   }
// }
// 点击轮播图右箭头
// const onNext = () => {
//   if (active.value >= slides.length - 1) {
//     active.value = 0
//   } else {
//     active.value++
//   }
// }
const next = () => {
  if (active.value >= slides.length - 1) {
    active.value = 0
  } else {
    active.value++
  }
}

let timer = -1
// 自动播放
const onPlay = () => {
  clearInterval(timer)
  if (!autoPlay) return
  timer = setInterval(() => {
    next()
  }, duration)
}
// 停止自动播放
const stop = () => {
  clearInterval(timer)
}
onMounted(() => {
  onPlay()
})

onBeforeMount(() => {
  stop()
})
</script>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;

  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }

    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;

      &.fade {
        opacity: 1;
        z-index: 1;
      }

      img {
        width: 100%;
        height: 100%;
      }
    }

    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;

      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;

        ~span {
          margin-left: 12px;
        }

        &.active {
          background: #fff;
        }
      }
    }

    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;

      &.prev {
        left: 20px;
      }

      &.next {
        right: 20px;
      }
    }
  }

  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>